INTESTINAL OBSTRUCTION
INTESTINAL OBSTRUCTION
OUTLINES OF PRESENTION DEFINITION CLASSIFICATION CAUSES SYMPTOMS EXAMINATION INVESTIGATION PSEUDO-OBSTRUCTION MANAGEMENT SURGERY : INDICATION DISCHARGE TAKE HOME MESSAGES
DEFINITIONAny form of impedance to the normal passage of bowel content through small or large intestine
CLASSIFICATION
• Partial vs complete• Mechanical vs non-mechanical
(functional)• Simple vs strangulated• Acute, subacute, acute on chronic,
chronic
CAUSES• ELDERLY – carcinoma, diverticulitis,
sigmoid volvulus• ADULT – hernia, adhesion, carcinoma• PAEDIATRICS – intussusception,
congenital hypertrophic pyloric stenosis, atresia (duodenum, ileum), meconium obstruction, volvulus neonatorum
CAUSESSMALL BOWEL OBSTRUCTION
LARGE BOWEL OBSTRUCTION
Intraluminal IntussusceptionsGallstone
Constipation
Intramural Crohn’s diseaseRadiation strictureAdenocarcinoma
AdenocarcinomaDiverticulitisIBD strictureRadiation stricture
Extramural AdhesionHerniaPeritoneal carcinomatosis
Volvulus
SYMPTOMS• Abdominal pain – true colic• Vomiting – high small bowel
greenish, bile-stained; low small bowel brown / faeculent vomit
• Distension• Constipation• Signs of strangulation – pain more
marked
EXAMINATION• Dehydrated, in pain, tachycardic• Toxic-looking, high temperature, hypotension
(might suggestive of strangulation)• Distended, visible peristalsis, scar, hernia
orifice• Tender, abdominal mass• Strangulation – tenderness more marked,
guarding, rebound tenderness• Bowel sound• PR exam – mass, faeces, blood
INVESTIGATION• AXR
• FBC: Hb anaemic (ca); PCV dehydration; TWBC strangulation
• RP: dehydration, AKI, electrolyte imbalance• ABG: alkalosis proximal obstruction;
acidosis strangulation• USG: to differentiate mechanical
obstruction & paralytic ileus• Colonoscopy• CT scan: level of obstruction, causes, sign
of strangulation
SMALL BOWEL OBSTRUCTION
LARGE BOWEL OBSTRUCTION
PARALYTIC ILEUS
Abdominal pain Colicky Colicky Minimal or absentVomiting Early, may be bilious Late, may be faeculent Present
Constipation + + +Other +/- visible peristalsis +/- visible peristalsisBowel sounds Normal, increased
Absent if secondary ileusNormal, increasedAbsent if secondary ileus
Decreased or absent
AXR Proximal distension (> 3 cm) + no colonic gasAir-fluid levels‘Ladder’ pattern
Proximal distension (> 6 cm) + distal decompressionAir-fluid levels‘Picture frame’ appearanceNo small bowel air (if ileocaecal valve competent)
Air throughout small bowel & colon
PSEUDO-OBSTRUCTION
PARALYTIC ILEUS• Temporary paralysis of myenteric plexus• Causes: Post-operatives, intra-abdominal sepsis,
electrolyte disturbances, medications (opiates, anaesthetics, psychotrophics)
• In post-op, normally resolves after 1 – 3 days
OGILVIE’S SYNDROME• Acute pseudo-obstruction• Causes: Trauma, infection, cardiac (MI, CHF),
disability (bedbound, paraplegia), drugs• AXR: caecal dilatation• Mx : Tx underlying cause
MANAGEMENT• DECOMPRESSION: NG tube• FLUID & ELECTROLYTE
- Fluid replacement NG tube loss- Correct electrolytes daily RP- Input/output charting CBD- CVP monitoring
• ANALGESIC
SURGERY: INDICATIONS
• Tumor, hernia• Failed conservative management• Peritonitis• Adhesion colic not resolved
DISCHARGE• BO + passing flatus• Tolerating orally• Haemodynamically stable• Abdominal distension resolves, bowel
sound normal• RP normal
TAKE HOME MESSAGES
• Define - impedance to the normal passage of bowel content
• 4 cardinal symptoms of IO: pain, vomiting, distension & constipation
• Common complication – electrolite imbalance (hypo k) and metabolic asidosis
• Bowel dilation : >3 cm small bowel , > 6 cm large bowel
• Adequate resuscitation & hydration• Common causes of obstruction in adult :
carcinoma
REFERENCES• Browse’s Introduction To The
Symptoms And Signs of Surgical Disease. Browse NL, Black J, Burnand KG, Thomas WEG.
• Principle and Practice of Surgery. Garden OJ, Bradbury AW, Forsythe J.
• Toronto Notes 2011